Method and apparatus for recording information from a slidable sheet of a rim cassette

ABSTRACT

A method and apparatus for recording the information from the slidable sheet (5) of a RIM cassette (2). The information included on the sheet, used especially in X-ray photography, is read from the sheet surface drawn out of the cassette with the aid of a laser beam focused on it, after which the sheet is emptied of information with the aid of a powerful light and returned to the cassette. According to the invention, the reading is effected during the linear withdrawal of the slidable sheet (5) in the reading position (9) past which the sheet surface including the information is guided, and the removal of the information is effected during the linear return travel of the slidable sheet in the emptying position (10) past which the sheet surface travels while the sheet is being pushed back into the cassette (2). The movement of the slidable sheet (5) can be effected by a pulling device which consists of a slide (8) travelling on a rotatable shaft (7) and the movement of the slide is effected with the aid of ball bearings mounted against the shaft at a pitch angle. The reciprocating path of the slide (8) is preferably adjusted so that the slidable sheet (5) comes only partially out of the cassette (2) which thus continuously acts as a guide for the sheet.

BACKGROUND OF THE INVENTION

The object of this invention is a method and apparatus for recordinginformation from a slidable sheet of a reusable image media (RIM)cassette, in which the information on the sheet surface drawn out of thecassette is read with the aid of a beam directed on it and the sheet isemptied of information after the reading and returned to the cassette.

There are materials which have the ability to be tuned by the effects ofradiation, such as x-ray, ultraviolet or gamma radiation directed onthem. The absorbable radiation energy may include information which canbe read with the aid of secondary radiation, such as a laser beam on thevisible light region which is directed onto the material, by recoveringthe light emitted from the material and by converting it to an image.This RIM technique is based on x-ray photography in which radiation,conducted through the photographed object and modified by the absorptionwhich occurs in the object, is focused on a layer of phosphor on thesheet which is to be excited. The phosphor layer records the informationincluded in the beam and the sheet which is exposed in this way is readby a laser beam in order to form an image on a light multiplier or film.

It is possible to form the X-ray image directly with the aid of areading head for the sheets connected to and in conjunction with thephotographing device. On the other hand, it is possible to enclose thesheet in the cassette after the exposure and to carry out the readinglater by a separate reading device. The latter technique, which thepresent invention relates to, is more flexible because the reading ofthe sheet enclosed in the cassette is not bound by time or place to thephotographing procedure.

The reading of the sheet in the cassette has so far been effected insuch a way that the sheet has been drawn out of the cassette onto a beltconveyor and the information on the sheet has been read in the readingposition with the conveyor moving. In order to achieve a successfulreading, the linear movement of the conveyor must be as smooth aspossible. After the reading, the sheet has been emptied of informationwith the aid of a powerful light on the path of the conveyor in asubsequent emptying position. After the emptying the sheet has beenreturned to the cassette to wait for the next operation.

SUMMARY OF THE INVENTION

The purpose of this invention is to establish a novel solution in orderto enhance the reading of the information on the slidable sheet in thecassette and the subsequent removal of the information from the sheet.The invention is characterized in that the reading is carried out,during the linear drawing out of the slidable sheet, in the readingposition past which the sheet surface containing the information isguided, and that the removal of the information is carried out, duringthe linear return travel of the slidable sheet, in the emptying positionpast which the sheet surface passes when the sheet is being pushed backinto the cassette.

In the solution according to the invention, the reading of theinformation on the slidable sheet can be initiated immediately after theend of the sheet has come out of the cassette, in contrast to the knowntechnique where the sheet has first been transferred to the conveyorbelt. Due to this improvement, the reading of the sheet is essentiallyspeeded up. According to the invention, the sheet makes a simplereciprocating movement with respect to the cassette during which theemptying of the information from the sheet is carried out in addition tothe reading of the sheet.

In the solution according to the invention, the movement of the slidablesheet with respect to the cassette and the reading and emptyingpositions of the sheet is essential. This is simply carried out in sucha way that the cassette is held in place and the sheet is arranged,during its reciprocating movement, to travel past the stationary readingand emptying positions. The movement of the sheet can thus be effectedby a pulling device which engages the end of the sheet and moveslinearly back and forth.

According to the invention it is preferred to arrange the reciprocatingmovement of the slidable sheet in such a way that the sheet only partlycomes out of the cassette during the movement. Thus the cassettecontinuously acts as a guide for the slidable sheet and no separatecontrol for taking the sheet back to the cassette is required.

It is also an object of the invention to provide a device for readingand recording the information on the slidable sheet of the RIM cassetteby the above method. The device according to the invention comprises ahousing equipped with a light-shield for receiving the cassette; anextension space for the housing into which the slidable sheet of thecassette can be drawn; a pulling device traveling back and forth in thespace by which the slidable sheet can be linearly drawn out of thecassette and pulled back into it; and members which are placed on theside of the reciprocating path of the slidable sheet for reading theinformation on the surface of the sheet in the reading position and forthe removal of the information that has been read from the sheet in theemptying position.

The housing can, in the device according to the invention, be comprisedof a cavity inside which the cassette can be fitted partly or fully andthe mouth of which is provided with a light-impermeable closure. In casethe cassette only goes partly inside the cavity, the closure can beformed of strips, ridges or similar members which are pressed againstthe sides of the cassette. In case the entire cassette goes into thecavity, the closure preferably consists of a cover which closes thecavity. It is essential that the closure prevents any outside light fromgoing into the space where the reading and emptying of the slidablesheet takes place.

The reading and emptying positions of the information on the slidablesheet advantageously lie adjacent on the front portion of thereciprocating path of the sheet, preferably as close as possible to theend of the space by which the slidable sheet comes out of the cassette.Thus the lengths of the movements required for the reading and theemptying of the sheet are the same and the length of the path of thesheet remains as short as possible.

The pulling device which propels the slidable sheet can be, according tothe invention, comprised of a slide mounted on a smooth shaft rotatablein opposite directions, with the slide traveling linearly on the shaftwith the aid of pitched bearings placed against the shaft. The slide isprovided with at least one guide which prevents the slide from rotatingwith the shaft. With the shaft manufactured and ground to precisetolerances, a linear movement of the slidable sheet is achieved by thissolution which is sufficiently smooth as regards the reading of thesheet. The accuracy of the movement is not dependent on the guide butonly on the manufacturing precision and the bearings of the rotatingshaft.

The engagement between the pulling device and the end of the slidablesheet can be arranged, in the device according to the invention, simplywith the aid of, for instance, a magnet included in the pulling device.In addition, the slidable sheet can be locked to the body of the pullingdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention is described in more detail with the aidof examples and by reference to the appended drawings, where:

FIG. 1 shows a device according to the invention for the reading ofinformation on a slidable sheet of a RIM cassette and the subsequentremoval of the information, in which the sheet is inside the cassetteand the slide which transfers the sheet linearly is in its initialposition,

FIG. 2 shows the reading of the sheet in the device according to FIG. 1with the sheet mainly drawn out,

FIG. 3 shows the sheet-propelling slide and the associated guide as asection III--III of FIG. 2,

FIG. 4 shows the slide and the guide as viewed from the top (indirection IV--IV of FIG. 2) and partly in section, and

FIGS. 5a-5c show a gradual recovery of information from the slidablesheet of the RIM cassette by using another device according to theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The device shown in FIGS. 1 and 2 comprises, as its main parts, body 1,cavity 3 which receives RIM cassette 2, extension space 4 of the cavitywhere slidable sheet 5 contained in the cassette carries out thereciprocating movement, pulled by slide 8 driven with the intermediaryof shaft rod 7 of stepping motor 6 which rotates around its own axle,reading and emptying positions 9, 10 for the information contained onthe sheet which are situated on the reciprocating path of the slidablesheet, with the associated members and protective casing 11.

Cavity 3 which receives cassette 2 includes entrance opening 12, ridges13 situated immediately behind the opening and pressed against the sidesof the cassette which prevent the outside light from getting furtherinto the cavity and space 4 behind it, guides 14 which lie against thesides of the cassette and cassette holder 15 with shoulder 16 at the endthereof. Cassette 2 can be pushed, according to FIGS. 1 and 2, throughcavity 3 up to said shoulder 16, whereby a portion of the cassetteremains outside the cavity.

Slide 8 which propels slidable sheet 5 is provided with magnet 17 withwhich the slide engages the end of the slidable sheet inside cassette 2,in the position according to FIG. 1. In FIG. 2, shaft rod 7 rotated bystepping motor 6 has transferred slide 8 near the opposite end of space4 with respect to cassette cavity 3, whereby slidable sheet 5 has beenmainly drawn out of cassette 2. After slide 8 and slidable sheet 5 havereached the extreme end of their paths, the direction of rotation ofshaft rod 7 is reversed, whereby slide 8 returns to the positionaccording to FIG. 1, pushing slidable sheet 5 back into cassette 2.

In X-ray photography the reading of the information recorded on thephosphor surface of slidable sheet 5 is effected, in the shown device,in reading position 9 during the withdrawal of the sheet. The deviceincludes mirror 18 which guides laser beam 19 of a wavelength of visiblelight in a reciprocating movement across the surface of the sheet andthe light emitted from the surface is conducted along light-conductingmember 20 to a light-multiplier (not shown). The emptying of slidablesheet 5 of information which has been read is effected during the returntravel of the sheet in emptying position 10, where a powerful emptyinglight is conducted on the surface of the sheet by light-conductingmember 21. Slidable sheet 5 which has been returned to cassette 2 isthus ready for a new exposure in the following X-ray photography.

FIGS. 3 and 4 show a mechanism which propels slide 8 drawing theslidable sheet on shaft rod 7. Slide 8 is provided with six ballbearings 22 inclined at a pitch angle which are arranged against shaftrod 7 on two groups of three parallel bearings. The rotation of rod 7around its longitudinal axis brings bearings 22 which are against therod into a rotating movement, and because the direction of shafts 23 ofthe bearings slightly deviates from the direction of rod 7, this resultsin the bearings forcing the slide into a linear movement along the rodwhich analogically corresponds to a movement of a nut on a screw thread.

In order for the slide to move in a desired way, linearly along shaftrod 7 without rotating with the rod, the slide is provided with guide 24comprised of lug 25 attached to the slide, fork portion 27 connected tothe lug with flexible link 26 and a stationary conducting rod 28. Forkportion 27 is provided with four screws 29 which contact conducting rod28 in a spotlike manner at the tips thereof and which are of nylon orteflon. Guide 24 has no effect on the smoothness of the linear movementof the slide but the smoothness is only dependent on the soundness andbearings of shaft rod 7.

The device for the reading and emptying of slidable sheet 5 of RIMcassette 2 of information, shown in FIGS. 5a, 5b and 5c, corresponds toa great extent to the one illustrated in FIGS. 1 and 2. However, thedifference is that cassette 2 is placed into the cavity in space 3 whichcan be closed by cover 30 in such a way that the entire cassette remainsinside the cover and that the reciprocating movement of slidable sheet 5is effected in a vertical direction. In FIG. 5, cassette 2 is pushedinto a hole made for it in body 1 of the device in such a way that thecassette extends to shoulder 31 in reciprocating slide 8 which isprovided with a magnet. In FIG. 5b cover 30 travelling in a tangentialdirection is transferred against cassette 2 in such a way that theentire cassette remains inside the cover. Pin 32 included in cover 30and loaded by a spring is thus against opening 33 formed in the body,and against the head of rod 34 in the hole which is included in slide 8,and the cover prevents the light from outside from entering into space 3under the cover and into reading and emptying positions 9, 10 of thesheet behind it.

When slide 8 starts moving from the initial position according to FIG.5b, rod 34 included in the slide retracts from opening 33 in the bodyand pin 32 included in cover 30 is pushed by the spring into the openinglocking the cover finally in place. The magnet included in slide 8 pullsslidable sheet 5 out of cassette 2 and the reading of the sheet iseffected with the aid of laser beam 19 in reading position 9 asdescribed above. In FIG. 5c slide 8 and slidable sheet 5 have arrived atthe end of their paths where entire slidable sheet 5 is outside cassette2, and after this the returning is effected to the position according toFIG. 5b during which the sheet is emptied of information in emptyingposition 10 as described above Cover 30 is finally opened according toFIG. 5a for the removal of cassette 2 and for the placing of a newcassette including a sheet to be read and emptied subsequently.

It is clear to those skilled in the art that different applications ofthe invention are not limited to the above examples, but can vary withinthe appended claims. Thus in FIGS. 5a-5c the reciprocating path of slide8 and slidable sheet 5 can be adjusted so that slidable sheet 5 does notentirely come out of cassette 2 but remains, even in its extremeposition, partly inside the cassette. The control of the movement ofslide 8 is further possible to arrange in another way than with the aidof guide 24 shown in FIGS. 3 and 4. It is, for instance, possible toplace slide 8 in a slide groove which is parallel with shaft rod 7 andsupport it there with nylon or teflon screws which contact the groove ina spotlike manner, whereby the arrangement prevents the slide fromrotating and thus forces it into a linear movement.

We claim:
 1. A method for reading the information on a tuned slidablesheet of a reusable image media cassette with the use of a separatereading device comprising the steps of:inserting a cassette with a tunedslidable sheet into a casing in a reading device; engaging one end ofsaid slidable sheet to a pulling device travelling linearly back andforth; moving said slidable sheet with said pulling device to draw saidslidable sheet out of said cassette in a direction of movement; focusinga light beam on said slidable sheet at a stationary reading position ona path of travel of said slidable sheet, said light beam readinginformation from said sliding sheet; reversing the direction of movementof said slidable sheet and returning said slidable sheet back into saidcassette; and emptying said slidable sheet of the information during itsreturn movement at a stationary emptying position on the path of travelof said slidable sheet.
 2. The method according to claim 1, wherein saidslidable sheet is pulled in such a way that it only partially comes outof the cassette.
 3. The method according to claim 1 or 2, wherein theinformation is read by focusing a laser beam on said slidable sheet andby conducting light emitted from said slidable sheet by the effect ofthe laser beam into a detector.
 4. A device for reading information froma tuned slidable sheet of a reusable image media cassette comprising:acasing equipped with a light-shield for receiving a cassette with atuned slidable sheet enclosed therein; an extension space for the casinginto which the slidable sheet in the cassette can be drawn; a pullingdevice engaging an end of the slidable sheet and reciprocating in saidextension space by which the slidable sheet can be drawn linearly out ofthe cassette and pushed back in; and members placed on a side of areciprocating path of the slidable sheet for reading of information onsaid slidable sheet in a reading position and for removal of theinformation which has been read from said slidable sheet in an emptyingposition.
 5. The apparatus according to claim 4, wherein said casing isformed by a cavity inside of which the cassette can be fitted fully orpartially and a mouth of which is equipped with a closure impermeable tolight.
 6. The apparatus according to claim 4 or 5, wherein the readingand emptying positions of the information are situated adjacent to eachother in a front portion of the reciprocating path of the slidable sheetclose to an end of said extension space from which the slidable sheetcomes out of the cassette.
 7. The apparatus according to any one ofclaims 4 or 5, wherein said pulling device consists of a slide mountedon a smooth shaft rotatable in opposite directions, said slide movinglinearly on the shaft with the aid of bearings lying against the shaftand placed at a pitch angle and is provided with a guide which preventsthe slide from rotating with the shaft.
 8. The apparatus according toany one of claims 4 or 5, wherein said pulling device comprises a magnetforming an engagement member which is attached to an end of the slidablesheet.